Go:如何在Go中使用func()bool参数?

这是Go中的示例代码 blackfriday 包裹:

package main

import (
    "bytes"
    "fmt"
    "github.com/russross/blackfriday"
)

func main() {

input := []byte(`##Title

- another paragragh

This is a being rendered in a custom way.
`)

    htmlFlags := 0
    renderer := &renderer{Html: blackfriday.HtmlRenderer(htmlFlags, "", "").(*blackfriday.Html)}

    extensions := 0

    unsanitized := blackfriday.Markdown(input, renderer, extensions)
    os.Stdout.Write(unsanitized)
}

// renderer implements blackfriday.Renderer and reuses blackfriday.Html for the most part,
// except overriding Link rendering.
type renderer struct {
    *blackfriday.Html
}

func (options *renderer) Header(out *bytes.Buffer, text func() bool, level int, id string) {
    fmt.Fprintf(out, "<custom link %q to %q>", content, link)
}

代码的目的是自定义 link 输出HTML的属性。

我也尝试过,但是 p 标签:

func (options *renderer) Paragraph(out *bytes.Buffer, text func() bool) {
    fmt.Fprintf(out, "<p class='custom'>%q</p>", text)
}

但结果是:

<h1>Title</h1>

<ul>
<li>another paragragh</li>
</ul>
<p class='custom'>%!q(func() bool=0x80a15d0)</p>

所以我不知道如何输出实际的文本( This is a being rendered in a custom way. ). 有什么想法吗?

这是函数的源代码:

func (options *Html) Paragraph(out *bytes.Buffer, text func() bool) {
    marker := out.Len()
    doubleSpace(out)

    out.WriteString("<p>")
    if !text() {
        out.Truncate(marker)
        return
    }
    out.WriteString("</p>\n")
}